Date: Sat, 6 Jul 1996 03:11:05 +0300 (EET DST)
From: Samuli Takala <tax AT cc DOT hut DOT fi>
To: Pin DOT F DOT Sun AT delorie DOT com
cc: djgpp AT delorie DOT com
Subject: Re: What is the quickiest way to clear memory?
In-Reply-To: <4rgv14$7ae@clark.zippo.com>
Message-ID: <Pine.OSF.3.93.960706030708.7215D-100000@alpha.hut.fi>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=ISO-8859-1
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On 4 Jul 1996 Pin DOT F DOT Sun AT delorie DOT com wrote:
> (use memset to clear a virtual screen memory is only twice faster than
> transfering data from virtual screen to video ram using movedatal function.
> As I know, data transfering to video ram is about 5-6 times slower than the
> to regular memories. So there must be a quicker way!)

memset should be about optimal for the job. On my system (486dx2/66 with
VLB ET4000/w32p), writing to the screen memory is actually faster than
writing to system memory (mode 13h and VBE 2.0 mode 101h with linear
frame buffer). Writing to screen can be done little over 40mb/s, but
system memory only accepts about 23-24mb/s.


Samppa

Samuli Takala      Samuli DOT Takala AT hut DOT fi       Finger tax AT hut DOT fi for more info.
See my homepage for Formula One Shadow Series: http://www.hut.fi/~tax/
		  "Kuorma-auto - Hyödyksesi tiellä"